Wednesday, July 28, 2010

$ mtr domainname-- MTR is computer software which combines the functionality of the traceroute and ping programs in a single network diagnostic tool.MTR probes routers on the route path by limiting the number of hops individual packets may traverse, and listening to responses of their expiry. It will regularly repeat this process, usually once per second, and keep track of the response times of the hops along the path.

$ host domainname-- In computer networking, a network host, Internet host, host, or Internet node is a computer connected to the Internet - or more generically - to any type of data network. A network host can host information resources as well as application software for providing network services. Internet hosts can generally be divided into server and client computers which generally communicate in the client-server model.

$ traceroute/tracepath domainname-- Traceroute/Tracepath is a computer network tool used to show the route taken by packets across an IP network.

$ ping domainname/IP-- Ping is a computer network admin utility used to test whether a particular host is reachable across an Internet Protocol (IP) network and to measure the round-trip time for packets sent from the local host to a destination computer, including the local host's own interfaces.

$ nslookup IP-- This command is often used to perform a reverse lookup on an IP address. Provide the authoritive and non-authoritative answers.

$ dig domainname/IP-- DNS lookup utility.

Websites: (Get more presentable information)

http://whois.domaintools.com/domainname-- Domain Name to Look up, GET Domain Registrar and owner details, billing address details, nameserver, A record and current STATUS of website.

http://my-addr.com/trace/domainname-- Trace (find path from current host) to some domain or hostname or an IP address.

Friday, July 16, 2010

The following points are guidelines to good software interface design, not an absolute set of rules to be blindly followed. These guidelines apply to the content of screens. In addition to following these guidelines, effective software also necessitates using techniques, such as 'storyboarding', to ensure that the flow of information from screen to screen is logical, follows user expectations, and follows task requirements.

Consistency ("Principle of least astonishment")

certain aspects of an interface should behave in consistent ways at all times for all screens

terminology should be consistent between screens

icons should be consistent between screens

colors should be consistent between screens of similar function

Simplicity

break complex tasks into simpler tasks

break long sequences into separate steps

keep tasks easy by using icons, words etc.

use icons/objects that are familiar to the user

Human Memory Limitations

organize information into a small number of "chunks"

try to create short linear sequences of tasks

don't flash important information onto the screen for brief time periods

provide appropriate articulatory feedback - feedback that confirms the physical operation you just did (e.g. typed 'help' and 'help' appear on the screen). This includes all forms of feedback, such as auditory feedback (e.g. system beeps, mouse click, key clicks etc.)

provide appropriate semantic feedback - feedback that confirms the intention of an action (e.g. highlighting an item being chosen from a list)

provide appropriate status indicators to show the user the progress with a lengthy operation (e.g. the copy bar when copying files, an hour glass icon when a process is being executed etc.)

System messages

provide user-centered wording in messages (e.g. "there was a problem in copying the file to your disk" rather than "execution error 159")

avoid ambiguous messages (e.g. hit 'any' key to continue - there is no 'any' key and there's no need to hit a key, reword to say 'press the return key to continue)

use modes cautiously - a mode is an interface state where what the user does has different actions than in other states (e.g. changing the shape of the cursor can indicate whether the user is in an editing mode or a browsing mode)

minimize preemptive modes, especially irreversible preemptive modes - a preemptive mode is one where the user must complete one task before proceeding to the next. In a preemptive mode other software functions are inaccessible (e.g. file save dialog boxes)

make user actions easily reversible - use 'undo' commands, but use these sparingly

Web page design

Download speed is a critical aspect of web page design. Remember that when you check your pages locally in your browser you aren't experiencing normal web delays! Regardless of your modem speed, pages will only download at the fastest rate of the slowest link in the 'chain' from a server to the browser. The following tips will help to speed downloads and aid comprehension of your web page materials:

avoid using 'blinks' unless these are absolutely necessary - blinks are distracting, use fonts, sizes, colors to attract attention

keep backgrounds simple and muted

minimize audio and video use, this really slows download time

use animated files (e.g. animated .GIFs) sparingly

use thumbnail .GIFs linked to larger .GIFs

specify .GIF size (HEIGHT, WIDTH) - this speeds download times

use 'ALTs' for .GIFs where only the .GIF provides the link - this provides linked text information to those only browsing in text mode

use image maps sparingly - they are slow and can be annoying - using an invisible table can often give similar results with much faster downloads

use frames sparingly and consistently - use absolute widths for frames, scroll bars, avoid menus for small numbers of items, also check that users don't get stuck in a frame

avoid 'construction signs' - web pages are meant to be dynamic and therefore should be changed/updated regularly - they are always under construction - try to tell users when content was last changed and what changes were made

remember that 50% of users have monitors 15" or less and at 640 x 480 resolution, so use a maximum window width of 620 pixels or flexible window widths and test your pages in your browser at low screen resolutions and limited colors (256 or less)

Thursday, July 8, 2010

To make special characters and accented letters show up on your pages, use a special set of codes called character entities, which you insert into your HTML code and which your browser will display as the corresponding symbols or characters you want.

The most common character entities have been collected by the International Organization for Standardization and compiled in the ISO Latin Alphabet No. 1 table, which includes special characters, letters with diacritical marks (accents, umlauts, etc.), and scientific and currency symbols. The Latin-1 table contains 255 characters.